Torque wrench with predetermined torque signaling means



Patented May 15, 1951 UNITED STATES PATENT O F F l CE 2,553,311; TDRQUE WRENHWTHCREEETRMINED TOR'QUE SIGNALING MEANS John Greer, Conimicutg. Re I;

Application October 28, 1944i, SeriaINo. 560,780

3 Claims.V (Cl. 81--52.f5)

This invention relates to wrenches or' the like of the type which are capable of registering the torque applied te the work'.

A-device'of this characterv comprises in general a head part which is provided With seine meansl for engagement withV the' Work,A a flexible beam" secured to the head andl a handle at the other end of the beam for applying' a turning force r torque to the Work. The resistance of tl'ieworkto theY torque applied will cause a deflection in the beam. This deflection may be measured or indcat'ed in terms of some particular unit of measure" by means of a pointer secured to a part of theA beam and relatively moving over' the face' of a properly graduated scale. Such indicating means are required to be in full View for" careful obserlf vation by the operator.

An object of the invention is to provide an indication which will be conveyed t0` the operatr even though heAvv is" not concentrating on his`v work.

Another object of the invention is to provide means by which the applicationl of a presetY torque is indicated' to the operatorv through his' tactil and hearing senses" inpadditionl to the usual indicator which requires the visual: observation of the operator.

Another object of the invention is to provide means by which the application of a presettorqu'e is indicated by means which will imparta physical sensation to theV hand of` the operator.

Another' object of the invention is to providemeans by which the application of a preset torque is indicated by an audiblev signal.

Another object ofthe invention is toprovi-de means by which the application of A a preset' torque will impart a physical sensation to the hand of the operator and also will sound an audible signal. n

With these and other objects in View, the in'- vention consists of certain novel features ofhc'on-k struction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings: y l

Fig. 1 is a top plan view of a torque measuring tool embodying my invention;

Fig. 2 is a View partly in section of a fragmental portion of the tool shownrin Fig. l on an enlarged s'cale showing the signalling mechanism Within the handle of the tool; y

Fig. 3 is a view similar to that shown in Fig'; 2

2, buit'- sliowing' thel elements thereofl in different relative"v positions;

Fig; i isi a sectional View taken substantially' albnglin 4"-4 of Fig. 2;

Fig'. 5" is a sectional viewv taken substantially along" line 5%5 ofv Fig. 2`; and

Fig". 6is a view of a fragmentai portion 0fl theshank' of'r theA t'ool-,

Referring to the drawings; Ii) designates generally a torque tool in the' form of a wrench Having a head I l provided with a square projection I2 for the reception of a socketed work' engag'ing' member (noti shown). To the' head there is attached a flexible shank I3 comprising" av centralresilient beam I4 and side* beams or bars l5v and IKE each' of a ler'igthl less than that of the' beam I4;.v Near the free endl portionsl of the'Y beam I4 there is" secured a bracketv II fo'rmedof' twojsubstantially similar elements IEB-"I9 bolted to the beam |14 as' at 20', more clearly shown in Fg. 4.

A ollow' handle 2| has one endmpivot'ally attfa'ched to' the'k bracket I1 by stud bolts` 22 extending" tl'irougli the- Walls of the handle and threadingl'y engaging the bracket I7 (see Fig. 4). The

bracket I'IV is provided*v with a slot 23 to snugly' receive a scale 24 in a position overlying the center beam I4 and also thefree end portions `of the" bars I5", I'B. The" scale may be secured inthe slot in vany suitableyinanner, such as by Welding.

Each bar f5 and I t carries 9, pointer' 25 extending over the graduated portion yof the scale: and has relative movement therewith so as to indicate the amount of deflection in the shank I3.

' The scale is graduated in a manner to express the deflection of the shank in terms' of a unit of torque applied such as inch pounds.

The beam I4 extends a substantial distance Within thehandle and has formed at the eXtreme end portion thereof opposed tabs 26, 2'! and a right angularly extending portion 28 to which there is secured in any approved manner a substantially l-sha'pe` member 29 for a purpose to K. be hereinafter" described.

In rder to oppose relative vpivotalr'nov'ement between the handle and the beam I4, 1I provide resilient yieldingflat springs `3 9' positioned one on either side of the beam It'. These springs 30 are bolted to the handle as at BI in cantilever fashion and are" formed so that their free ends engage the tabs 25, 21 and resiliently resist movement between the handle and beam. As a force is applied to the handle, the handle and beam I4 will move as a unit until the torque applied exceeds the opposing value of the force of the spring 30 with which the beam may be associated. The action may occur in either direction in which the torque is applied.

The springs 30 are adjustable so as to provide variable opposing values to the relative movement between handle and beam. This is accomplished by means of a member 32 in the form of a screw bolt having a shank 33 which is journaled in the rear wall 34 of the handle and is provided with a head 35 which forms a shoulder collar 36 surrounds a portion of the Shank 33' within the handle and is lockedon the shank by a pin 31 which extends through the shank providing an abutment engageable by the collar. A spring 31' encircles the shank with one end thereof abutting the rear wall and the other end the collar 36, thus resiliently opposing longitudinal movement of member 32. portion 38 of member 32 threadingly receives a disk 39 which has formed therein opposite slots 43, 4! through which the springs 30 pass. The member 32 may be rotated by means of the head 35 so as to move disk 35 along the threaded portion 38, soA as to shorten or lengthen the effective length of the springs 30. As the disk is moved towards the free endl of the springs the same will be stiffened and when moved towards the anchored end thereof more resiliency will be provided, thus presenting different opposing values against movement between the handle and the beam.

Within the handle is a signalling mechanism generally designated 42 which is mounted on a bracket 43 secured to a sidewall of the handle. The signalling mechanism comprises two sub- The threaded stantially identical separate mechanisms 44, 45.

The mechanism 44 being operable when the torque is applied in a clockwise direction and the mechanism 45 is operable when the torque is applied in a counter-clockwise direction. Each mechanism comprises bell 46 and a clapper 41 which is placed under tension by a relative movement of the handle and beam and which upon- 52 and the other end abutting a washer 55 surrounding the guide and resting on the shank 48. The free end of the shank 48 is beveled and positioned in the path of movement of one ofthe arms 56 of the Z-shape member 29 heretofore described.

In using the wrench the tension of the springsV 30 are preset for providing the proper opposing value for the predetermined torque to be applied to the work. When the predetermined force has been reached in the application thereof to the work there will be a relative movement between the handle 2| and beam i4 which will move either one or the other of the arms of the member 29 into-engagement with one or the other A compression spring 54 encircles the guide 58 in the space between the arm 52 and shank 48 with one end thereof abutting the armV 4 of the shanks 48 depending upon the direction in which the force is applied and will move the same in a direction to compress the spring 54. The direction of the movements of the shanks 48 are in a straight line, while that of the member 29 is on an arc. When the shank 48 has traveled a sufficient distance the same will slide oit the end of arm 56 and permit a quick expansion of spring 54 to move the clapper 41 into contact with the bell. Upon release of the tension and the return of the parts to normal position, the end of the arm 56 will engage the bevel on the end of the shank 48 and move the same out oi its path of movement. The opening in the arm 53 being elongated and the guide 58 having suicient clearance with the opening in arm 52 to permit such movement of the shank. The shank is returned to normal position by means of a pull spring 51 secured at one end thereof and at the vother end to a pin 58 carried by the bracket.

I claim:

l. In a torque applying tool, a resilient beam having work-engaging means at one end thereof, a handle for moving said beam for applying a torque to a Work-piece, said handle and beam being secured to each other for relative movement, a pair of opposed leaf springs carried by said handle for engaging said beam on each side thereof for yieldingly opposing relative movement between said handle and said beam, means slidable along said leaf spring to preset the opposing value thereof, a signalling means'an abutment carried by said beam and movable into engagement with said signalling means to actuate the same upon sufficient relative movement between said handle and said beam predetermined by the opposing value of the preset leaf springs.

2. In a torque applying tool, a resilient beam having means at one 'end thereof for engaging a work-piece, a handleforV moving said beam for applying a torque to the work-piece through said beam, said handle and beam being secured'to each other for relative movement, resilient means carried by said handle and engaging Vsaid beam on each side thereof for yieldingly opposing relative movement between the handle and said beam in either a clockwise or counter-clockwise direction, an abutment carried by said beam, a signalling means including a spring-pressed, movably mounted clapper secured to said handle and having a portion thereof initially positioned in the path of movement of said abutment to be engaged thereby and-moved upon relative movement between said handle and said beam in a direction to increase the spring pressure thereon.

3. In a torque applying tool, a lresilient beam having means at one end thereof for engaging a work-piece, a handle for moving said beam for applying a torque to the work-piece through said beam, said handle and beam being secured to each other for relative movement, resilient means carried lby said handle and engaging said beam on each side thereof for yieldingly opposing relative movement between the handle and said beam in either a clockwise or counter-clockwise direction, an abutment carried by said beam, a signalling means including a spring-pressedymovably mounted clapper secured to said handle and having a portion thereof initially positioned-in the path of movement of said abutment to be engaged thereby and moved upon relative movement between said handle and said beam in a direction to increase the spring pressureY thereon, Vsaid clapper being A mounted for movement in Va 5 straight path whereby said clapper will be disengaged from said abutment upon suicient relative movement between said handle and said beam to permit said clapper to be moved under spring pressure in the opposite directien.

JOI-11N J. GREER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Zimmerman July 29, 1941 Number Number Number 

